[Beastmaster]

That's what I thought. Here's the problem that I see.

Bottom loaded coils on low frequency transmissions will have a tendency to emit more radiation from the coil on upward.

So, if the coil is under the roof rack grid, the majority of the signal will end up being bounced between the ground plane of the roof and the roof rack grid.

If you were to look at a normal vertical antenna from the side, it would emit in a pattern similar to what you would see in a McDonald's arch logo, or similar to a bagel being cut in half abd you create an "m" shaped thing out of it.

When you have the coil between the grid, the propogation will end up getting cut off and you'll end up with only a transmission pattern that is aimed pretty much upward.

The funny thing - grounding the rack will merely add to transmission woes in theory, since you're sandwiching the coil part of the antenna between two actual ground planes.

So, I'd see if I could put the magmount on the grid of the rack, and ground the rack.